Rake tooth for carbonizing acid bowls



Apr. 17, 1923. 1,451,926

A. c. SARGENT RAKE TOOTH FOR CARBONIZING ACID BOWLS Filed March 15, 1920 5 win W606 Patented Apr. 1'7, 1923.

UITED STAS T FFEQE.

ALLAN C. SARGENT, OF WESTFOBD, MASSACHUSETTS, ASSIGNOR TO C. G. SARGENTS SONS CORPORATION, A CORPORATION OF MASSACHUSETTS.

RAKE TOOTH FOR CARBONIZING ACID BOWLS.

Application filed March 13, 1929.

To aZZ whom it may concern.

Be it known that I, ALLAN C. Sancnxr, a citizen of the United States, residing at \Vestford, in the county of Middlesex and State of Massachusetts, have invented a new and useful Itake Tooth for Ca'rbonizing Acid Bowls, of which the following is a specification.

This invention relates to the rakes which are used for moving the stock to be treated in carbonizing acid bowls. The solution used in such bowls contains from two to four per cent of sulphuric acid and as this attacks all metal work with which it comes in contact. the rakes are usually made of wood. It is well known, of course, that lead is an acid resisting material but it is so soft that it has not been used practically for the teeth of these rakes. The principal object of this invention is to provide a rake having teeth that will resist the action of the acid and that will be strong and durable.

Reference is to be'had to the accompanying drawing which is an edge view of a rake showing two forms of teeth therein, both coming within the scope of this invention, two of these teeth being shown in central section.

The invention is shown as applied to a rake head 10 of the usual construction, that is, preferably made of wood. This is pro vided with a series of perforations equally spaced apart for the reception of the shanks of the teeth. In one form shown, each of these teeth comprises an iron core 11 having one or more circumferential grooves 12 and provided with an outer casing 13 formed mainly of sheet lead. The sheet lead consists of a pipe or tube which is placed on the iron core and provided'with circumferential inwardly extending beads 14 fitting in the grooves 12. These are forced into the grooves by the beading operation so as to securely hold the casing in position. Their upper ends are flared at 15 so as to fit against the bottom of the rake head.

I prefer also to extend the casing beyond the end of the core 11 and cut it off square at the end at a distance from the same. In the recess thus provided, a lead plug 16 is provided to seal the end, but it is the beading that holds the casing on the core. This seals the ends against the admission of the acid Serial No. 365,674.

solution and it will be noted that the entire lead casing is impervious to the liquid.

The core which may be of other metals than iron, such as brass, if desired, is provided with a screw threaded end 17 extending up through one ofthe perforations in the rake head. It is held in position by a nut 18.

The above description applies to all of the teeth shown except the one at the top of the sheet in which a continuous cylindrical core 21 is employed for receiving the cylindrical lead tube or pipe 28, In this case, the walls of the core and easing being smooth throughout, the casing is held in position by flaring the upper end of the tube 25 against the rake head to provide a circular space around it of a material size. This space is then filled in with solder to form a circular ring 29 surrounding the core and preferably entering the screw threads of the end 27, or it may be sweated on the core to hold it firmly in position. A plug 26 is formed, preferably as: in the other case.

A tooth constructed in either of the ways described has a strong central core which can be firmly and securely mounted on a rake head, and yet is provided with an outer surface which will not be attacked or penetrated by the acid solution employed. It is a strong, durable construction, in view of the use to which it is put and is a material improvement in this art over the prior constructions with which I am familiar.

The plugs. 16 and 26 constitute an important feature because they furnish not only a thin covering but an acid resisting end on the tooth which, being subject to considerable wear, should be of a material thickness. The cores of these teeth will not come into cont-act with the acid until these plugs are worn clear through, obviously insuring a long life for the rake.

Although I have illustrated and described only two forms of the invention, I am aware of the fact that modifications can be made therein by those skilled in the art within the scope of the invention as expressed in the claims.

Therefore, I do not wish to be limited to all the details herein shown and described, but what I do claim is 1. As an article of manufacture, a rake for use in a carbonizing bowl, comprising a tooth having a strong metallic core and a casing of a material not detrimentally affected by acid, said core having circumferential grooves on its surface and said casing being beaded into said grooves to hold it in position.

2. As an article of manufacture, a rake for use in a carbonizing bowl, comprising a head and a tooth secured thereto, involving a strong metallic core and a casing of a material not detrimentally affected by acid, said casinghaving a, flaring end extending against the rake headffor assistance in securing it thereto and a body of soft metal located in the space between said flaring end and the rake head to fasten it thereto.

3. As an article of manufacture, a rake comprising a head and teeth secured thereto, each involving a strong metallic core and a casing of lead, said casing having a flaring end extending against the rake head for as sistance in securing it thereto, the core extending through the rake head and being fastened to it on the back.

In testimony whereof I have hereunto affixed my signature.

ALLAN o. SARGENT. 

